At the scene of the crime, in the museum’s west wing, Angela found some wood chips, so she slipped them into her purse for future analysis. They were allegedly from an old wooden mask, which the guard said he threw at the would-be thief. Later, in the lab, she determined the age of the chips, using a sample which contained 10 g of carbon and showed a ¹⁴C decay rate of 100 counts/min. How old are they?